Air cooling system for combustion engines



Aug. 11, 1931.

G. E. REED ET AL AIR COOLING SYSTEM FOR COMBUSTION ENGINES Filed Dec. 27, 1927 2 Sheets-Sheet 1 I VENTOR.

Maw/aw;

ATTORNY Aug. 11, 1931.

G. E. REED ET AL 1,818,868

AIR COOLING SYSTEM FOR COMBUSTION ENGINES Filed Dec. 27, 1927 2 She ets-Sheet 2 By (Zr/a9 ATTO NEY.

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Patented Aug. 11, 1931 y PATENT ol-Flcs UNITED STATES? GEORGE .E. REED AND JOHN W. REED, OF SYRACUSE, NEW YORK AIR COOLING SYSTEM FOR COMBUSTION ENGINES Application filed December 27, 1927. Serial No. 242,596.

This invention relates to an air cooling system for internal combustion engines as applied more particularly to motor vehicles.

. The main object is to bringthe several 5 cylinders into more compact relation than has heretofore been vpractised in the con-. struction of air-cooled engines and at the same time to reduce the length and weight of the'engine by casting all of the cylinders 10 en bloc with relatively short and narrow connecting webs.

Another object is to provide the cylinders with heat-radiating tins of relatively high a heat conductivity arranged in parallel 1 spaced relation at right angles to a plane passing through the longitudinal centers or axes of the cylinders and connecting webs soas to afford a far greater heat transfer area than has heretoforebeen possible in 29 engines having their cylinders cast en bloc.

"Another object is to provide the cylinders with a removable head having similar heatradiatingfins preferably in vertical alinement withthe fins ofthe cylinders so as to 25 form continuous vertical air passages be tween the fins ofboth sets.

-A further object is to bring the intake and exhaust ports and their corresponding valves-as nearly as possible in the longitu dinal center of the head and'to converge the side walls of the head toward said ports to reduce to a minimum theconducti ve distance between the centers of the exhaust valves and the adjacent cooling fins and thereby to expedite the dissipation of the heatfrom the heat at the sources of maximum temperature.

Another object is to provide theengine with an air-jacket of sheet metal of relatively high heat- 'conductivity extending alongth'e oppositesidesand rear end of the cylinders and across theouter edges ofthe 'fins in heat transfer relation thereto'to form suitable chambers for the circulation of air theret-hrough and through the spaces between the fins for cooling purposes.

A further object is to arrange the valves and ports in planes at an acute angle to each other merging in the longitudinal cen- 459: ter of the cylinder head to further facilitate described.

the cooling ofthe head and particularly the walls of the exhaust ports therein. 7 Other objects and uses relating to specific parts of the engine and cooling system will be brought out in'the following description. In the drawings e i 7 Figure 1 is a transverse vertical sectional view through one of the cylinders and crank case of aninternal combustion engine and air-circulating passages together with the I heat transfer fins and one-of the ports and valve for controlling the same, together with the cam shaft and its inclosing case and the means for clamping the cylinder head to the cylinderblock. V v Figure 2- is a side elevation, I partly in section and partly broken away, of the engine and cooling system shown in Figure 1 in which the four cylinders are cast en bloc. Figurev 3' is a horizontal sectional .view taken in the plane of line 33, Figure 2.

As illustrated, this engine comprises a plurality of, in this'instance four, upright cylinders -l which are cast en bloc from suitable metal such as cast iron, with relatively short and narrow connecting webs -2. and-2 in a plane passing through the vertical axes of the cylinders to bring the cylinders in close compact relation. and thereby. to reduce the length and weight of the engine and at the same time exposing practically the entire peripheral areas of 'the'severalcylinders to the coolingv influence of the surrounding atmosphere for dissipatlng the heat therefrom. That is, the transverse widthofjthe' webs 2 and 2 is lessthan 411% of the'diameter of the'bore of'anyone of. the cylinders, this ratio taken in connection with the peculiar distribution and relative widths of the heat radiating fins being foundto be most eflicient in maintaining' the temperature of the cylinders below a safe limit or more specifically below the 1 limit of flash ignition of the piston lubricating oils as will be hereinafter more fullv 5 T The cylinders *1 are mounted upon a crank case -3 in which the crank shaft 4. is journaled,'said crank shaft being connected by pitmen 5 to suitable pistons 6 for reciprocating the latter within their respective cylinders .1-.

The upper ends of the cylinders lare capped by a suitable head 7- which is held in place by clamping bolts -8 having their lower ends engaged with the undersides of lugs -9 on opposite sides of the intermediate portion of the cylinders and their upper ends engaged with the upner faces of lugs -10- on opposite sides of the head 7 as shown more clearly in Fig ure 1. Y

The lugs -9- at each side of the cylinder are preferably arranged in pairs, those of each being spaced apart to permit the lower ends of the bolts to be placed between them with the head of the bolt engaged with the underside of the corresponding pair of In like manner the lugs -10- at each side of the longitudinal center of the head 7- are arranged in pairs, those of each pair being spaced apart to receive the upper ends of the bolts 8, having their nuts as 8' engaged with the upper faces of the corresponding pair of lugs l0- so that when the nuts -8 loosened the bolts may be withdrawn laterally from their respective lugs 9- and 10.

The bolts 8 are preferably flat in cross section and arranged edgewise with reference to the longitudinal center of the engine so that they may be conveniently placed between adjacent cooling fins on the cylinder -1 and its head 7-.

It is, of course, understood that when the head 7 is clamped to the u per end of' the cylinders 1 suitable pac ing will be employed to form a gas-tight joint.

The head'-7- is provided in its lower side with chambers 11 alined with the combustion chambers as -l2 of the cylinders1 and having their opposite sides converging upwardly, each chamber 1l being provided with an intake port 18 and an exhaust port -l4.- extending upwardly from the apex thereof at an angle to and to one side of the axis of the cylinder.

These ports -13 and -14- are controlled by separate valves 15 and 16 having their stems extending upwardly from said apex through suitable guide openings in the upper walls of their respective ports at an angle to and to the other side of the axis of the cylinder and are yieldingly held in closed positions by springs 17, Figure 1. I

The ports -l3 and 1 iand the corresponding valves --15 and 16- are therefore disposed in upwardly diverging planes intersecting each other in the longitudinal center of the head so that the portion of the head 7- in the horizontal plane of the valves '15 and 16 is contracted transversely to bring the relatively thin side walls thereof into close heat-transfer relation to those parts of the engine which are subjected to the highest temperatures.

A cam shaft housing l8 is removably secured to the top face of the head 7 to inclose the upper ends of the valve stems and also to receive and inclose a cam shaft -19 and its cams -20 which serve to open the valves 15- and l6 against the action of their springs -17- as the cam shaft l9 is rotated in suitable time relation to the movements of the pistons 6 as usual in four cycle engines of this type.

Air cooling system The upper ends of the cylinders -lin which the combustion chambers l2- are formed and also the connecting webs 2 and 2 are provided with vertically disposed fins 2l arranged in uniformly spaced parallel relation lengthwise of the engine or at right angles to a plane passing through the axes of the cylinders and having their inner edges cast into the peripheries of the cylinders and opposite upright faces of the webs and their outer edges disposed in vertical planes parallel with the plane passing through the axes of the cylinders.

The upper edges of the fins 21- are disposed in substantially the same horizontal plane as the upper ends of the cylinders while their lower edges are disposed in a horizontal plane closely adjacent but slightly above the lower ends of the combustion chambers 12 to afford ample space for the circulation of air from the underside upwardly through the spaces between the In like manner the head 7 is provided with vertically disposed fins -22 projecting from opposite sides thereof in uniformly spaced parallel relation lengthwise of the engine and extending from the upper ends of the cylinders some distance above the contracted portion of the head in which the valves 15 and l6 are seated.

The outer edges of the upper portions .of the fins -22 are disposed in vertical planes parallel with and some distance from the corresponding sides of the head 7 While the outer edges of thelower portions of said fins .-22- are flared outwardly and downwardly to approximately the width of the underlying fins -22- on the cylinders to form continuations thereof.

That is, the fins 22 on both sides of the head 7 are preferably in vertical alinement with the fins 2l on corresponding sides of the cylinders -land webs 2' and 2 so as to form. intervening vertical air passages through which the air may be circulated for cooling purposes.

ameter of the cylinders to allow the finsto be continued around'practically the entire peripheries of'the cylindersand thence along the webs insubstantially. the same spaced relation for producing a greater combined heat transfer area than has heretofore been practiced. That is, the" fins 21 and 22 are made of sheet metal and of far greater heat conductivity than the cast metal of the cylinders and webs and contribute materially in preventing the rise of tempera ture of the cylinders abovea safelimit previously mentione a Y Furthermore, the oppositejheat radiating surfaces of these the double purpose of'keeping the temperature of the cylinders within safe limits and also of reducing the frictional resistance to the passage of the} cooling air along; and between the fins. Y i

'Another, feature of the invention lies in the fact that the combined widths of the opposite surfaces of the fins withiiran' ar'c of approximately degrees from thecenter line ofthe six times the'diameter of-the b'ore of any one cylinder and constitutes a further, means for keeping the temperature of the cylin ders within safe limits," this approximate ratio having been demonstratedito be'p r'ac tical'and most efficient. 1

The outer edges of the fins leading from the end webs 2- are connected by sheet metal plates -23-, preferably of the same material such as copper, to t e outer ends of the fins which extend outwardly from the" central longer web 22-, These plates 23: extend-downwardly from the upperen'ds and 'ac ross the outer edges of the cylinder fins -2l 'to suitable seats 24 on opposite sides of the' upper portion of the "crankcase, '3'-so as to lie in vertical planes some distance from the walls of the cylinders'and parallel with :a plane passing said cylinders thereby forming air chambers 25 extending lengthwise of theengine from front to rear between the lower edges of the fins +21 and upper walls'of the crank case -3- as shown in"Figure 1.

ofthe fins -'-22 in heat transfer relation fins are parallel and serve engine cylinders is more than through the vertical' axes of Additional plates -23"-v fare eirtendede thereto and in vertical alinement with the corresponding. side plates -23.- to form continuations thereof, the upper edges of said: plates -23 converging 'upward1y.:.to conformto the upwardly converging outer edges of the adjacent fins. l

These chambers 25 communicate with the verticalspaces between thefins 21 and .--22- so that cold air entering *both chambers. :may lfind through the spaces between the fins. Anyirsuitable means'may be employed for forciblycirculating. atmospheric air :through the chambers --25-,and thence upwardly through the spacesbetween the fins -'-21- andi22i-- which spacesrare open at the top to allow free exit ottheheated air. 'As. illustrated this circulating means comprisesfa rotary fan --27"- mounted upon an upright shaft -28-- on the front end of the engine, said tem being inclosed within: a case29 forming a contiuation of'the side plates -Q3-. I

The lower and upper walls of the 'fan case 28- are provided with circular openings concentric with theqrotary fan -27 to admit atmospheric air from the lower and; upper ends of: the fan, case ,intotheinteriorthereof where it is forcibly circulated through both of the chambers --25'- and thence upwardly through the spaces between the fins ,21-' and -22.

The rearmost fins as -21 are extended downwardly across' the rear endsof the chambers 25- to close the same and thereby to cause the deflection of the currents of air. from said chambersupwardly between the remaining! fins 2l and T hat is, the :side plates-@13 and-23+- extend downwardly from theintermediate portions fof 'the fins-22Y to the top of the crankcase -3- and across the outer edges ofcthe fins -2L- and 22-and have their rear ends. connected tothe corresponding outer L edges of the rearmost fins --21- while their-frontends are connected-to the two opposite sides walls ot-the fan case 29: to form theair chambers and therbyYito confine and di'rect the circulationiof air; from the fan case '-29' through free exit upward y Pic which impedes the rearward movement 'between the fins the air currents and causes the; air to pass upwardly from the chambers 25 between the chambers +21fand -22- to escape to :the atmosphere at thetp f h ,fins-'22 7 These side plates 23""and 23- tols of: the chambers- -25'' gether with the rearmost fins 21-. also are made of thin sheet copper of high-heat conductivity to receive the heat from the fins 21- and Q2 and thereby greatly add to the heat transfer area of the cooling system.

The outer edges of two of the fins -21- leading from opposite sides of the webs 2 are connected by vertical plates -3l to the outer edges of two of the fins 2l leading from opposite sides of the next web 2 and extend across the outer edges of the intervening fins in spaced relation to the plate 23 to receive heat from said intervening fins and from the webs and thereby to further increase the heat transfer area of the cooling system; C

The head 7- which is common to all of the cylinder! is provided with suitable sockets -32 for receiving spark plugs, one for each cylinder. As previously stated, the clamping bolts --8 are fiat transversely and arranged at diametrically opposite sides of each cylinder, the purpose in fiattening the bolts being to enable them to pass bet-ween adjacent fins -21- and -22 of the cylinders l and head -7- respectively as shown more clearly in Figure 3.

The lower end of the fan shaft 28* may be operatively connected to the crank shaft 4- of the engine by any suitable power transmitting device arranged within a suitable gear case -33- on the front end of the crank case -3-.

Operation When the engine is in operation the fan 27- will be rotated at suitable speed to take in the cool atmospheric air through the openings 30- and to circulate said air rearwardly through the chambers -25- andthence upwardly between and against the fins 21 and 22 which rapidly take up the heat transferred thereto from the engine cylinders land head 7- and owing to the large surface areas of the fins togetherwiththeir high heat conductivity, the heated air transferred thereto is rapidly dissipated and allowed to escape at the upper ends of the fins aided by the force of the air currents produced by the operation of the fan '27-, it being understood that the plates 23'and 31, together with the rearmost plates -2ladd Inate-- rially to the rapidity of heat transfer and dissipation of the heat to the atmosphere and that the relatively narrow't-webs 2 and -2 connecting the cylinders and to which some of the fins are connected, additionall expedite the transfer of heat from the cylinders to the atmosphere.

I It will also be observed that the particular parallel vertical relation of the fins and their projection from the cylinders and webs in the manner described enables those fins to be extended, laterally indefinite distances, but preferably within the width of the "crank case without interference with each other thereby producing a maximum heat transfer area capable of dissipating the heat developed by the operation of the engine under all climatic temperatures in addition to affordingfree natural upfiow of the air between and against the fins aided or expe dited by the forcible circulation of the air through the operation of the rotary fan -27.

We claim 1. In an air-cooling system for an upright internal combustion engine having a cast metal cylinder, a plurality of vertically disposed sheet metal fins projecting outwardly from the opposite sides of the cylinder in parallel spaced relation and having their lower ends terminating in a plane above the lower end of the combustion chamber of the cylinder.

2. An internal combustion engine cylinder having lengthwise relatively narrow webs projecting from diametrically opposite sides thereof, lengthwise fins projecting from opposite sides of the cylinder and webs in parallel spaced relation at right angles to a plane passing through the axis of the cylinder and webs, and a heat transfer plate connecting the outer upright edges of the web-fins.

3. An internal combustion engine cylinder having lengthwise relatively narrow webs projecting from diametrically opposite sides thereof, and lengthwise vertically disposed fins projecting from opposite sides of the cylinder and webs in parallel spaced relation at right angles to a plane passing through the axis of the. cylinder and webs, said fins having their lower ends terminating in a plane above the lower ends of the combustion chambers of said cylinders.

it. An internal combustion engine comprisinga plurality of cylinders arranged in line connected by intervening relatively narrow lengthwise webs, and fins projecting from the cylinders and webs in parallel spaced relation at right angles to a plane passing through the axis of the cylinders and a heat-transfer plate extending across the outer upright edges of the cylinder fins and connected to the web-fins. L

5. An internal combustion engine comprising a plurality of upright cylinders arranged in line, vertically disposed sheet metal fins projecting outwardly from opposite sides of the cylinders in parallel spaced relation, and upright sheet metal plates in direct contact with the outer edges of the end fins of each cylinder, and engine-driven means for circulating air vertically through the spaces between the fins,

6. In a multlple cylinder internal combustion englne having a removable head, and

' lteadfin parallel spaced relation, said head.

' width projecting having tapered ignition continuations of the combustion chambers of the cylinders, each chamber having an inlet port and an exhaust port in its apex, self-closing valves for said ports, and engine-driven means for opening the valves.

7. In a cooling system for internal combustion engines, the combination with an upright cylinder having webs of unequal from diametrically opposite sides thereof, said cylinder having an intake port adjacent the wider web and an exhaust port adjacent the narrower, web, and vertically disposed wardly from opposite sides of the Webs in parallelspaced relation and at right angles to a direct line passing through the axis of,

the cylinders and centers of both webs.

8. In a cooling system for internal conibustion engines, the combination with an upright cylinder having webs ofunequal radial length projecting from diametrically opposite sides thereof, said cylinder having an intake port adjacent the web oi? lesser radial length and an exhaust port adjacent the web of greater radial length, and vertically disposed fins projecting laterally from opposite sides of the webs in parallel spaced relation, the web of greater radial length having a greater number of laterally projecting'fins than the one of lesser radial length.

9. An internal combustion engine com I prising a plurality of cast-metal cylinders in line and cast en bloc with intervening webs along the center line, said webs being of considerably less Width than the bore of any one of the cylinders, and sheet metal fins, of greater heat conductivity than the cast metal, projecting outwardly from opposite sides of the cylinders and webs in spaced parallel relation at right angles to the center line of the cylinders. V g j 10. An internal combustion engine as in claim 9 in which the opposite surfaces of the fins are parallel. g 11. An internal combustion engine as in claim 9, the ratio of combined width of the opposite surfaces oi the fins within an arc of 4:5 degreesfro'm said. center line to the diameter. of the bore of any one cylinder 1s. greater than six to one.

12. In an upright multiple cylinder internal combustion engine having a removable head, said head having vertically disposed sheet from opposite sides of the'head in parallel spaced relation and at right angles to a plane passingthrough the axes of said cylinders.

1.3. In an upright multiple cylinder internal combustion engine having a head and vertically disposed sheet metal fins projectchambers forming fins projecting out 7 upper ends metal fins projecting outwardly ing from opposite sides of the head in parallel spaced relation and at right angles to a plane passing through the axes of said cylinders,'said head having upwardly tapered ignition chambers forming continuations of the combustion chambers of the cylinders, each chamber having an intake port and an exhaust port in its apex, self closing valves controlling said ports, and engine driven means for opening said valves.

14. In a multiple cylinder internal combustion engine having a tapered head, upright fins projecting from opposite sides of the cylinder in parallel spaced relation and clamping bolts between adjacent fins and having their lower ends operatively connected to the cylinders near the lower. ends ofthe combustion chambers and their movable laterally into and out of engagement with the head for holding and releasing the head in and from its, operative position, said clamping bolts being of less width. than the distance between adjacent fins to prevent contact therewith.

15. An internal combustion engine comprising a plurality of cast metal cylinders in line and cast en bloc with intervening webs along the center line, the webs of each cylinder being of unequal width and length,- the wider webs having the shorter length, and sheet metal fins projecting outwardly "from opposite sides of the. cylinders and webs in equal spaced parallel relation at right angles to a plane passing through the axis of the cylinders.

16. An internal combustion engine as in claim 15 in which each of the cylinders are provided with an intake port adjacent the web of lesser length, adjacent the web of greater length.

In witness whereof we have hereunto set our hands this 16th day of December, 1927.

' GEORGE E. REED.

JOHN W. REED.

and an exhaust port 

